Windows HPC Server 2008

Windows HPC Server 2008, released by Microsoft on 22 September 2008, is the successor product to Windows Compute Cluster Server 2003. Like WCCS, Windows HPC Server 2008 is designed for high-end applications that require high performance computing clusters (HPC stands for High Performance Computing). This version of the server software is claimed to efficiently scale to thousands of cores. It includes features unique to HPC workloads: a new high-speed NetworkDirect RDMA, highly efficient and scalable cluster management tools, a service-oriented architecture (SOA) job scheduler, an MPI library based on open-source MPICH2, and cluster interoperability through standards such as the High Performance Computing Basic Profile (HPCBP) specification produced by the Open Grid Forum (OGF).

In June 2008, a system built collaboratively with the National Center for Supercomputing Applications (NCSA) and Microsoft ranked #23 on the Top500 list, a ranking of the world's fastest supercomputers, with a LINPACK score of 68.5 teraflops. The NCSA supercomputer uses both Windows Server HPC and Red Hat Enterprise Linux 4. As of November 2011, that ranking has since dropped to #253.

In the November 2009 rankings published by Top500, a Windows HPC system built by the Shanghai Supercomputer Center achieved a peak performance of 180.6 teraflops and was ranked #19 on the list. As of November 2011, Windows HPC has about 0.2% (1 out of 500) of the market of the 500 most powerful supercomputers, with about 0.2% of total gigaflops, with Linux dominating the rankings with 91.4% and Unix second place with 6%. The other two systems in the top 100 that can run Windows HPC do so only part of the time.